Filter.



H. REISERT.

FILTER.

APPLICATION FILED JUNE 26', 1913.

1,088,929 Patented Mar. 3, 1914.

3 SHEETS-SHEET 1.

fQ/VESSES H. RBISERT.

FILTER.

APPLICATION FILED JUNE 26, 1913.

1,088,929, Patented Mar. 3, 1914.

3 SHEETS-SHEET 2.

WITNESSES 'Q COLUMBIA PLANOGRAPII Coy-WASHINGTON, n C

H. REISERT.

FILTER.

APPLICATION FILED JUNE 26, 1913.

1,088,929. Patented Mar. 3, 1914.

3 SHEETS-831E121 3.

WITNESSES v INVENTOR flag? @4144 14km. 7s W6 flaw-m .4 RNEYS COLUMBIAPLAWGRAPN GIL-WASHINGTON. D. C-

HANS REISERT, OF COLOGNE, GERMANY.

FILTER.

Specification of Letters Patent.

Patented Mar. 3, 1914.

Application filed June 26, 1913. Serial No. 775,978.

To all whom, it may concern Be it known that I, HANS Rnrsnnr, a subjectof the Empire of Germany, and residing in. Cologne, Germany, haveinvented a new and useful Improvement in Filters, of which the followingis, a specification.

This invention relates to filters, and the object is to provide animproved construction of filter having, a plurality of beds, wherebylarge capacity can be secured in small space or the filtering action canbe differentiated, according to the particular purposes in view, andwhereby, also, all the beds can be washed out by singlemeans forproducing rapid backward How of clear water.

The invention accordingly comprises a plurality of filter beds, whichare superposed one above the other, and a chamber of ade quate capacitybelow the beds for the reception of filtered Water from all of them, sothat by the introduction of air under pressure into this chamber theclear water can be driven back through the several beds so as tothoroughly wash out the accumulated impurities, this action beingpromoted by the agitation of the material of the beds caused by theforceful flow of the wash water.

In one embodiment of the invention the filters comprise a coarse orpro-filter bed, to which the unfiltered water is supplied, and two ormore beds of relatively fine material below the pre-filter bed, togetherwith provisions whereby the water which percolates through thepre-filter is divided so that different parts thereof flow through thedifferent fine beds, the filtrates from the latter rejoining in thechamber or reservoir beneath. In this way the speed of filtrationthrough the fine beds is one-half or one-third or other fraction,according to the number of these beds, of the speed through the coarseor prefilter bed, which is an advantage since the filtering off of thebacteria which is effected in the fine beds demands a slower speed offiltration than the removal of the mere mechanical impurities which aretaken out in the pre-filter bed. Moreover, in the washing-out operation,also, the speed with which the clear water passes through the fine bedsis less than the speed with which the reunited washing currents passthrough the pro-filter bed, and this is as it should be because thesecondary beds being of fine material loosen themselves more easily thanthe pre-filter bed, which is composed of heavier material, and, also,because the mud which is taken off from the secondary beds is finer andcan consequently be removed more easily than the mud from the coarsefilter, which demands a strong backwash for its removal. In anotherembodiment of the invention the raw water is divided among all of thefilter beds, in which case the latter may all be of the same kind ofmaterial.

In the accompanying drawings I illustrate two specific constructionsembodying the principles of my invention, but it will be apparent tothose skilled in the art that numerous other embodiments are possible.

In these views: Figure l is a vertical longitudinal section through oneof the constructions; Fig. 2 is a cross-section through the same showingit in normal operation; Fig. 3 is a view similar to the last but show"ing the filter during the wash-out operation; Figs. 4 and 5 are viewscorresponding to Figs. 2 and 3 but showing a different construction; andFig. 6 is a fragmentary detail view on an enlarged scale.

Reference will first be had more particularly to Figs. 1 to 3 inclusive.The filter here shown has three beds 1, 2, 3 resting on suitableperforated supports 4, 5, 6 and surrounded by suitable walls 7. Asindicated, the bed 1 or pre-filter bed is of coarse material, while thesecondary beds 2, 3 are of fine material.

Means are provided over the top bed for supplying raw water for all thebeds. As shown this means comprises a trough-like receptacle 8,extending longitudinally of the filter and having an opening or openingsalong its bottom, and a deflecting plate 9 beneat-h the same whereby thewater is delivered laterally so that the flow through all portions ofthe bed is substantially uniform. The raw water is admitted to thetrough 8 through a pipe 30 leading from a suitable source.

Beneath the lowest bed is a chamber 10 inclosed within the walls? and ofsuch capacity as to hold suflicient water for washing out all of thebeds by rapid backward flow, which is produced by admitting air underpressure to tho upper part of the chamber through a pipe 11 leadin froman air compressor or other suitabe source.

hand, so that when the air is admitted to the chamber it forces thewater before it back ward through the beds. The wash water thus impelledpasses through the beds either in succession or individually, as thecase may be. As shown in Fig. 3 the backward flow of wash water, withthe impurities which it carries away, escapes over the tops of the walls7 into the gutters 12, whence it passes out through the openings 13.During the normal operation of the filter the clear water is drawn offfrom the chamber 10 through an exit indicated at 14, which exitisiclosed during the wash-out operation.

The water-sealed means of communication between the filter beds and thewash-out chamber is shown as being provided for by an air-tight wall 15between the chamber and the lowermost bed, and one or more tubes ordowntakes 16, which open at their upper ends through the said wall andplunge into the water in the chamber, extending almost to the bottomthereof. Obviously these downtakes may be of other than tubular form. Inthis construction all the water passes through the pre -filter and thendivides, part of the flow passing through each of the fine filters. Tothis end a wall 17 is disposed between the beds 2 and ,3 so as to cutoff communication between them, and inlet and. outlet ducts 18 and 19are provided opening at one end through this wall. The ducts 18 extendupward over the bed 2, so as to receive part of the water that has percolated through the bed 1 and conduct it through the bed 2, out of contacttherewith, to the bed 3. The ducts 19 extend clownward below the bed 3,so as to conduct away the water that has percolated through bed 2without coming in contact with the bed 3. The ducts 19 preferablydeliver into the upper ends of the tubes 16, as shown; and

there may be one or any suitable number of each kind of ducts, butpreferably there is a definite, predetermined relation between the totalcross-sections of the ducts and downtakes. 'Thus, the totalcross-sectional areas of the downtakes 16 is equal to the combined totalcross-sections of the ducts 18 and 19; and the total cross-sections ofthe two kinds of ducts are equal to each other. The ducts arepreferably, though not necessarily, tubular, and are of such ample crosssection as to permit rapid washing out of the beds.

In operation, with this construction the entire supply of raw waterpercolates through the pre-filter 1. The filtrate from this bed entersin part into the fine bed 2 and in part into the ducts 18, by which thispart is conducted to the fine bed 8. In this way the fiow is dividedapproximately into two equal parts. The part which percolates throughthe bed 2 is prevented by the wall 17 from passing through the bed 3,and. in-

stead is conducted downward by the ducts 19, so as to enter thedowntakes 16. The water that percolates through the bottom bed joins thefiltrate from bed 2 and both pass by way of the downtakes into the washout chamber. Thus it. will be seen that I provide means for dividing theflow that has passed through the coarse or pre-filter bed and collectingthe combined filtrates of the fine beds in such manner as to enable itto be utilized to wash out all the beds when desired. The speed offiltration through the fine beds, as also ofthe backward flow of washwater, is half the speed through the ,larly' to the beds in the otherform, but in this instance they are all of the same size of material.Here, also, the fiow of the Water is divided between the beds andreunited in the wash-out chamber 10, but the division iseflected as toall of the beds, so that it is the raw water which is divided, a part ofit flowing through each bed, the filtrates of all the beds comingtogether in the downtakes 16. For this purpose communication 1s cutimpervious walls 20 and 21.. Ducts 22 extend downward from the openingsin the wall 20 through the bed 2 so as to carry off the filtrates frombed 1" out of contact with the bed beneath. In like manner ducts 23extend downward from openings in the wall 21 through the bed 3, so as tocarry off the filtrate of both beds 1 and 2 out of contact with bed 3%.As shown, the ducts 22 and 23 are preferably in alinement, duct 23 ineffect constituting an extension of duct 22 but beingof increasedcross-section because of the increased fiow, The water from bed 2 isenabled to enter the passage 22, 23through suitable openings asindicated. Similarly, the downtakes 16 are preferably arranged as afurther continuation of the ducts, being of great-er diameter than thesections 28; and the filtrate from bed 3 is enabled to reach thedowntakes by the provision of suitable openings, as in the case of bed 2With the construction shown it will be seen that in. effect I providecontinuous downtakes extending through two of the beds and into thewash-out chamber, the filtrate from the top bed entering the upper endsof these downtakes and the filtrate from the other beds finding theirway into the same through entrances beneath the respective beds.

The raw water reaches the top bed directly from the supply trough 8 buta part only percolates through this bed. The rest, amounting toapproximately twothirds,

off between the beds 1" and 2 as well as between the beds 2' and 3*,there being two flows down through one or more ducts or pipes 24, thesame passing through the bed 1 to an opening in the wall 20, with whichit makes a tight joint. Part of the water from the duct 24; escapesthrough this wall onto the bed 2, while the remainder, or approximatelyone-third of the total flow, coi'itinues down a narrow duct 25, which isin alinement with the duct 24 and delivers to the bed 8 through anopening in the wall 21, there being a tight joint at this point also.

It will be evident that with this construction the raw water is dividedinto several parts, which pass through the beds individually, thefiltrates from all the beds passing through the downtakes 16 to thewash-out chamber 10. In order to wash out the beds air under pressure isforced into the chamber through the pipe 11*, and the clear water rushesup the downtakes and divides. Part of it is forced upward through thematerial of bed 3 and then escapes through ducts 25 and 24:. Anotherpart is forced through bed 2 and escapes through duct 2 L; while thelast part washes through bed 1.

As will be apparent to those skilled in the art numerous othercombinations of beds and ducts may be effected without departing fromthe spirit of the invention. Thus, there may be various arrangementscombining what may be termed successive and parallel flow. The firstconstruction shown herein is successive as to the flow through beds 2and 8, while the second construction is illustrative of what may betermed parallel or multiple flow.

Fig. 6 illustrates the preferred construction of the perforated supportson which the beds rest, the same comprising two perforated plates withwire mesh between.

What I claim as new is:

1. In a filter, the combination of a plurality of superposed filterbeds, means over the top bed for delivering the water which is to passthrough the several beds, means for dividing the "flow of water fromsaid means so that different parts of it pass through the material ofdifferent beds, a chamber beneath the beds to receive the filtered watertherefrom, and means for admitting air under pressure to said chamber soas to drive the water therein upward through the beds.

2. In a filter, the combination of a plurality of superposed filterbeds, means for dividing the water to be filtered so that differentparts thereof pass through the material of different beds, a chamberadapted to receive filtered water from all the beds and to hold asuflicient quantity to wash out the same, and means for forcing thefiltered water in said chamber backward through the beds when desired.

3. In a filter, the combination of a plurality of superposed filterbeds, a chamber beneath the same for receiving the filtered water fromthe several beds, means for dividing the flow of water comprising ductsleading downward from one or more of the beds through the bed or bedsbeneath, and means for forcing the clear water in said chamber backthrough the beds and ducts for washing out when desired.

4:. In a filter, the combination of a plurality of superposed filterbeds, a chamber beneath the same for receiving the filtered water fromthe several beds, a wall between said beds and, chamber, one or moredowntakes extending into the latter soas to afford water-sealed means ofcommunication between the beds and chamber, means for admitting airunder pressure to said chamber when desired so as to force the waterbackward through said downtakcs to wash out the beds, and ductsextending downward from one or more of the beds through one or more bedsbeneath so that the filtrate from the bed or beds above reaches saidchamber without passing through the material of the bed or beds below.

In a filter, the combination of a plurality of superposed filter beds, achamber peneath the same for receiving the filtered water from theseveral beds, a wall between said beds and chamber, one or moredowntakes extending into the latter so as to afford water-sealed meansof communication between the beds and chamber, means for admitting airunder pressure to said chamber when desired so as to force the waterbackward through said downtakes to wash out the beds, a wall between twoof the beds, and one or more ducts extending downward from said wallthrough the bed or beds below and delivering into said downtakes.

6. In a filter the combination of a plurality of superposed filter beds,a chamber beneath said beds to receive the filtered water therefrom,means whereby the water which percolates through an upper bed is dividedso that different parts thereof are caused to percolate throughdifferent beds below, and means for forcing the water in said chamberbackward through the beds when desired.

7. In a filter, the combination of a plurality of superposed filterbeds, and means for cutting off communication between certain beds andfor conducting water to the lower and from the upper of these beds, saidmeans comprising a division wall between the beds and ducts which openat one end through said wall and extend, respectively, upward over thebed above the wall and downward below the bed beneath the wall.

8. In a filter, the combination of three or more superposed filter beds,comprising a relatively coarse pre-filter and finer beds beneath, meansfor supplying the water to be filtered to the pre-filter, and means fordividing the water that percolates through the pre-filter among the finebeds, the last-mentioned means comprising a wall between said fine bedsand ducts at opposite sides of the wall leading downward, respectively,to the fine bed beneath the wall and from the fine bed above the wall. a

9. In a filter, the combination of a plurality of superposed filterbeds, comprising a pre-filter bed and secondary filter beds 7 amongwhich the waterfrom the prefilter bed is divided, a chamber beneath thebeds to receive filtered water therefrom, a wall between said chamberand the beds, and one or more downtakes plunging into the water in saidchamber so as to afford water-sealed means of communication between thebeds and chamber, in combination with a wall cutting 01f communicationbetween the secondary filter beds, one or moreinlet ducts leading fromabove the upper of these secondary beds to the lower thereof, one ormore outlet ducts leading from the upper of said beds below the lowersecondary bed, and means-for admitting air under pressure to saidchamber to force the water therein gacclkward through the downtakes,ducts and v 10. In a filter, the combination of a plurality ofsuperposed filter beds, comprising a pre-filter bed of coarse materialat the top and secondary filter beds of fine material beneath the same,means for supply ing to the pre-filter bed the raw water that is topercolate through the several beds, a chamber of substantial capacityfor the reception of filtered water from all the beds, and means wherebyair may be forced into said chamber so as to drive the clear waterbackward through al the beds for washing out.

11. In a filter, a plurality of superposed filter beds, means t-hereoverfor supplying 'the raw water, a chamber beneath the beds ing the bedsand inlet and outlet ducts leading through the beds and opening throughthe last-mentioned wall or walls.

12. In a filter, the combination of a plurality of superposed filterbeds, means for supplying raw water thereto, a wash-out chamber forfiltered water, water-sealed means of communication between the beds onthe one hand and the chamber on the other hand, a Wall or walls cuttingoff communication between adjacent beds, and ducts passing throughcertain beds for directing the fiow with reference to other beds.

In testimony whereof, I have signed my name to this specification, inthe presence of two subscribing witnesses.

HANS iainsnnr.

Witnesses:

W. F. Brssrnc, J. J. KOZINN.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

' Washington, D. G.

